New fluorinated dienes and process for preparing same

ABSTRACT

Fluorinated dienes are disclosed which have the formula RF - CF CH - CH CF - RF&#39;&#39; I wherein RF and RF&#39;&#39; may be the same or vary and represent a straight or branched saturated fluoro-carbon radical CnF2n 1, and n is a whole number between 1 and 20. The radical may also contain a few atoms of hydrogen and halogens other than fluorine. A method for the preparation of these fluorinated dienes is also disclosed.

United States Patent Riess et a1.

NEW FLUORINATED DIENES AND PROCESS FOR PREPARING SAME Inventors: Jean G.Riess; Maurice Le Blane;

Georges Santini; Jacky Guion, all of Nice, France Assignee: ProduitsChimiques Ugine Kuhlmann, Saint-Denis, France Filed: Jan. 31, 1975 Appl.No.: 545,894

Related U.S. Application Data Division of Ser. No. 446,101, Feb, 26,1974, Pat. No. 3,901,948.

Foreign Application Priority Data Feb. 28, 1973 France 1, 7307107 U.S.Cl 260/6533; 260/6535 Int. Cl. C07C 17/28 Field of Search.... 260/653.3,653.1 T, 653.1 R

Primary Examiner-D. Horwitz Attorney, Agent, or Firm-Pennie & Edmonds[57] ABSTRACT Fluorinated dienes are disclosed which have the formulaR,CF=CHCH=CFR,' 1 wherein R and R may be the same or vary and representa straight or branched saturated fluoro-carbon radical C F and n is awhole number between 1 and 20. The radical may also contain a few atomsof hydrogen and halogens other than fluorine. A method for thepreparation of these fluorinated dienes is also disclosed.

2 Claims, N0 Drawings NEW FLUORINATED DIENES AND PROCESS FOR PREPARINGSAME This is a division, of application Ser. No. 446,101 filed Feb. 26,1974 now US. Pat. No. 3,901,948.

DESCRIPTION OF THE INVENTION 1. Field of the Invention This inventionrelates to fluorinated dienes and a method for their preparation.

IL Description of the Prior Art The compound tetrafluorobutadiene F,C=CH-CH =CF, II is known in the art but this compound does not fall withinthe framework of the present invention because R and R substantiallydiffer from F.

K. L. Paciorak, B. A. Merkl and C. T. Lenk, in volume 27 of the JOURNALOF ORGANIC CHEMIS- TRY, page ll5 (1962) describe the following compound:

Although the article describes a compound (III) which approaches thecompound (I) of the claimed invention, it neither suggests nor disclosesthe compounds (I).

The present invention involves the discovery that by reacting the twocompounds R 'CF I and R,.-CF CH CI-I with copper in the presence of asolvent according to the reaction:

R,-'CF,I k cF, CH cu, 2c, Solvent one obtains a mixture of compounds (IVand l) R r CF CH cH,CF,R,-' (IV) and R, CF CH CH =CF R,-' (I).

The initial reagents R 'CF I and R CF CH CH are known (Hazeldine,J.CHEM.SOC., 1949, page 2856).

These compounds are extremely difficult to separate. The applicantshave, however, discovered that by varying the conditions of thereaction, it is possible to produce the compound (I) alone. This is anunexpected and surprising result.

The applicants have found that at relatively mild experimentalconditions, for example hours at 120C, a mixture of approximatelypercent of the compound of the formula (IV) and 80 percent of thecompound of the formula (I) resulted which was difficult to separate.However, when more severe conditions, i.e., prolonged heating or highertemperature were applied, it was unexpectedly found that the compound offormula (I) was obtained exclusively.

SUMMARY OF THE INVENTION The present invention involves compounds offluorinated dienes having the formula R,-CF=CHCH=CFR," I in which R; andR are the same or different and each represents a+fluorocarbon radicalcontaining 1 to 20 carbon atoms (C,,F where )1 equals 1 to 20). Thecompounds which are the subject of the present invention are alsocapable of containing a few atoms of hydrogen or halogens other thanfluorine.

The method of preparation of the compounds of formula (I) can berepresented b the e uation: R,'CF,! R,CF,CH=CH, 2 u -CF CHCH=CFR,-' B

This reaction may be carried out at a temperature from about l20C toabout 150C for a period between about 10 hours to about 72 hours. Thereaction time may vary and is approximately inversely proportional tothe temperature. Some examples of solvents that can be used includedimethyl formamide (DMF), dimethyl sulphoxide (DMSO), an aromatic orheterocyclic amine such as pyridine, a heavy ether of the ethylenepolyoxide type, a glycol dimethyl ether (glyme), or any other suitablesolvent.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The above reaction (B) containsan excess of approximately ,5 to I00 percent of the compound R,-'CF,Iabove the stoichiometric quantity required and about 2 to 5 gram atomsof copper per mole of R 'CF I. The copper which can be used in the abovereaction may be, for example, copper produced by displacement reactionCuSO +Z l .Cul ZnSO, or copper produced via the reduction of CuO.

The reaction time and the temperature vary in inverse proportion. Forexample, for a temperature of 120C a reaction time of about 72 hours isnecessary, while at 150C the formation of the compound (I) in apreponderant quantity is observed after only about l0 hours.

Tetrafluorobutadiene may be prepared in accordance with the abovereaction (B) by reacting the compound of the formula HCF CH=CH and thecompound CF;,[ in a molar excess of approximately 5 to percent, in thepresence of approximately 2 to 5 gram atoms of copper per mole of thecompound CF l, in a solvent at a temperature of between about C andabout l50C for a time to produce exclusively or substantiallyexclusively tetrafluorobutadiene. Examples of solvents that may be usedare mentioned above.

The new compounds of the present invention can be used as monomers forhomopolymerization or copolymerization with fluorine dienes or withethylenically unsaturated hydrocarbons, such as propylene by standarddiene polymerization or copolymerization techniques in which latterinstance they may be used to form polymers (films, for example) withstain resistant properties.

In addition, the fluorinated diolefins of the invention have excellentphysical properties for use as oxygen transport in biological systems(i.e., synthetic blood and other uses). B way of illustration C5I-I"CF=C CH =CFC,H-, has a density of 1.689 and at 37C under 760 mm Hg theabove fluorinated diolefin can dissolve 41.5 ml of oxygen per 100 ml and222 ml of CO per 100 ml of the olefin.

Fluorocarbons have been recognized as having utility as blood substitutein animals. See, for example, the publication CHEMISTRY, Vol. 46(8),Sept. 1973, pp. 20 and 2 l.

The following examples illustrate the invention in a nonrestrictivemanner.

EXAMPLE I A mixture of C F CF I (0.062 moles) and C F CF: CH CH (0.05moles) was heated with 10 g of powdered copper produced via thedisplacement reaction of CuSO, with Zn, and 50 mls of anhydrous DMF atl40C for about 72 hours. After extraction with ether and centrifuging soas to eliminate the cop- Analysis C H F 5, calculated for C HJ-" 27.380.38 72.24 7: found in reaction product 27.6l 0.45 7 L88 The compoundobtained is liquid and distils at 38C under 0.5 mm Hg. The compound wasidentified by its nuclear magnetic resonance spectrum (NMR).

EXAMPLE 2 Analysis C H F calculated for C H,F 26.84 0.32 72.84 9? foundin the reaction product 27.04 0.35 72.51

The compound obtained is a liquid which distils at 54C under 0.4 mm Hg.The compound was identified by its NMR spectrum.

EXAMPLE 3 The mixture of Example 1 was heated to 150C in DMF. Thepercent conversion into the desired compound C F CF CH CH CF C -,F equalto percent after about 18 hours. In DMSO the percent of conversion isequal to 70 percent after about 18 hours.

EXAMPLES 4 to 7 By repeating the conditions of Example 1, the followingcompounds were prepared:

These compounds are identifiable by their distillation temperaturesunder reduced pressure and/or their melting point as indicated above, aswell as by their NMR spectra.

We claim:

1. A process for the preparation of tetrafluorobutadiene, whichcomprises reacting the compound of the formula H CF CH CH and thecompound CF I in a molar excess of approximately 5 to I00 percent, inthe presence of approximately 2 to 5 gram atoms of copper per mole ofthe compound CF 1, in a solvent at a temperature of between about C andabout C for a time to produce exclusively or substantially exclusivelytetrafluorobutadiene.

2. A process according to claim 1 wherein the solvent is selected fromthe group consisting essentially of dimethylformamide, dimethylsulphoxide, heavy ethers, glycol dimethyl ether (glyme), aromatic aminesand heterocyclic amines.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTIONPATENTNO.: 3,925,491 DATED December 9, 1975 INVENTOR(S) Jean G. Riess etal.

tt is certified that error appears in the aboveidentified patent andthat said Letters Patent are hereby corrected as shown below:

Column l,line 61, "a+fluorocarbon" should read -a fluorocarbon-- Column2, line 15, "approximately- 5" should read approximately 5-.

Signed and Ercaled this thirteenth Day of April1976 [SEAL] A ties r.-

RUTH C. MASON C. MARSHALL DANN Arresting Officer (mmnissinm'r of Parentsand Trademarks

1. A PROCESS FOR THE PEPARATION OF TETRAFLUOROBUTADINED, WHICH COMPRISESREACTING THE COMPOUND OF THE FORMULA HCF2-CH=CH2 AND THE COMPOUND CF3LIN A MOLAR EXCESS OF APPROXIMATELY 5 TO 100 PERCENT, N THE PRESENCE OFAPPROXIMATELY 2 TO 5 GRAM ATOMS OF COPPER PER MOLE OF THE COMPOUND CF3L,IN A SOLVENT AT A TEMPERATURE OF BETWEEN ABOUT 120*C AND ABOUT 150*C FORA TIME TO PRODUCE EXCLUSIVELY OR SUBSTANTIALLY EXCLUSIVELYTETRAFLUOROBUTADINE.
 2. A process according to claim 1 wherein thesolvent is selected from the group consisting essentially ofdimethylformamide, dimethyl sulphoxide, heavy ethers, glycol dimethylether (glyme), aromatic amines and heterocyclic amines.